In the proposed work we will determine if there are specific differences in the chemical composition of the components of the membranes of normal and tumor cells, with emphasis being placed on the glycoproteins of the plasma membrane. The composition of the membranes will be determined by isolating them from the cells and analyzing their components by means of acrylamide gel electrophoresis, Sephadex and ion exchange chromatography, and quantitative determination of their sugar components. The pattern of synthesis and release of these components will be studied to determine if there is a difference in such patterns in normal and tumor cells. These studies will be carried out by studying the rates of incorporation and release of radioactively labeled precursors of proteins and sugars in membranes. We also will determine if the macromolecular material released from cultured animal cells into the medium are derived from cell membranes. These studies will be carried out by analyzing the released components in the same manner as the isolated membranes and determining if their composition is similar to that of the membrane components. The possible relationship of the new glycoproteins found in the serum of patients with tumors to cell membrane components will be investigated.